1. Field of the Invention
The present invention relates to an optical disk apparatus to be mounted on an electronic equipment such as a personal computer, a notebook computer, a mobile terminal equipment or the like, and an optical pickup advantageously employed in such optical disk apparatus.
2. Description of the Related Art
As an optical recording medium, various optical disks such as a DVD (digital versatile disk), a CD-R (recordable compact disk), a CD-RW (rewritable compact disk) and the like are being developed. In the DVD, information recording or reproduction is executed with a laser beam of a wavelength of about 650 nm. Also in the CD-R or CD-RW, information recording or reproduction is executed with a laser beam of a wavelength of about 780 nm. There is proposed an optical disk apparatus for executing information recording or reproduction on the optical disks of such plural types.
Also in such optical disk apparatus for executing information recording or reproduction on the optical disks of such plural types, as a light source for an optical pickup mounted on the optical disk apparatus, there are employed plural laser elements emitting light beams of different light beams arranged in adjacent manner in a package (so-called hybrid 2-wavelength semiconductor laser) (refereed to JP-A-10-241189) or light sources of plural wavelengths integrated on a semiconductor substrate (so-called monolithic 2-wavelength semiconductor laser).
However, though the configuration described in JP-A-10-241189 does not show a very large heat generation in the light source because the distance of the light sources is relatively large, the monolithic 2-wavelength semiconductor laser when employed as the light source shows a very high heat generation because it is of a monoblock structure with very close light beam emitting positions, thereby resulting in drawbacks such as a shortened service life of the light source.